Sen. Barack Obama told the nation's mayors on Saturday that current urban policy is obsolete and needs to be replaced by a model that focuses on rational metropolitan growth rather than chiefly on inner-city crime and poverty.

Drawing on his years as a community organizer on the South Side of Chicago, Obama, the presumptive Democratic presidential nominee, said that while he intends to be a supportive partner if he wins the White House, the mayors should not count on significant additional help from Washington. Change, he said, comes from the bottom up, not from the top down.

He also said Washington's ability to help the cities would be limited in part by a long-term federal budget deficit left by the Bush administration, which he called "the most fiscally irresponsible administration in modern times."

"Yes, we need to fight poverty. Yes, we need to fight crime," Obama said in an address to the U.S. Conference of Mayors. "Yes, we need to strengthen our cities. But we also need to stop seeing our cities as the problem and start seeing them as the solution. Because strong cities are the building blocks of strong regions, and strong regions are essential for a strong America."

Obama also used the speech to criticize Sen. John McCain, the apparent Republican presidential nominee, for visiting flooded areas of Iowa after voting against financing for some water projects and flood control programs.

"I'm sure they appreciated the sentiment," Obama said, "but they probably would have appreciated it more if Sen. McCain hadn't opposed legislation to fund levees and flood control programs, which he considers pork."

He was referring to a $23 billion water bill passed by Congress last year and vetoed by President Bush because he said it was laden with unnecessary spending. McCain opposed the bill on the same grounds. Congress later overrode the veto, which contained billions of dollars in projects earmarked for members' districts.

McCain took the weekend off from politicking, but his campaign responded with a charge of its own - that while McCain sponsored an amendment to the water resources bill to provide new financing for Army Corps of Engineers flood control programs, Obama opposed it.

"Barack Obama's willingness to continue the status quo pork-barrel politics in Washington, and then engage in political attacks that entirely disregard the facts, once again fundamentally shows that he's nothing more than a typical politician," said Tucker Bounds, a spokesman for McCain.

In his speech to the mayors, Obama said the federal government should provide aid in building and repairing the roads, rail networks, electrical grids, water systems and telecommunications networks that stitch together metropolitan areas. He promised a $60 billion, 10-year program of infrastructure development.

But he said cities and states should invest more in education to produce the workforce needed to compete in a global economy.

He promised to untangle the maze of federal bureaucracy that has grown up over decades that makes it difficult for mayors to know where to turn for federal assistance. He also promised to appoint the first White House director of urban policy, to be an advocate in Washington for the cities.

Rocky race relations

As Sen. Barack Obama opens his campaign as the first African American on a major party presidential ticket, nearly half of all Americans say race relations in the country are in bad shape and 3 in 10 acknowledge feelings of racial prejudice, according to a new Washington Post-ABC News poll.

Obama will be forced to confront these views as he seeks to broaden his appeal. He leads in the Post-ABC poll by six percentage points among all adults, but among those who are most likely to vote, the contest is a toss-up, with McCain at 48 percent and Obama at 47 percent.

To win in November, Obama most likely will have to close what is now a 12-point deficit among whites. (Whites made up 77 percent of all voters in 2004; blacks were 11 percent, according to network exit polls.)

The poll was conducted among a national random sample of 1,125 adults. The results from the full poll have a margin of sampling error of plus or minus three percentage points, while the error margin is larger for subgroups; it is four points among whites.